Posted 10 April 2011 - 08:43 AM
Kibud Av requires, besides actions, that a person not think of his parents with disrespect., or as his equal. Kibud Av requires one to look at their parents as a prominent person in their eyes. (see Sefer Chareidim ch. 1 Mitzvos Hateluyos Belev, Chaye Adam 67:3. According to the Aruch HaShulchan, "kibud" only requires actions, but the obligation of "moreh" includes thoughts.)
The way to accomplish this is, you should try to find good traits in your parents and focus on them more than you would in a regular person. It is perfectly OK not to be objective here - that is exactly what the Halachah wants you to do. Also, we know that actions have a tendency to affect our attitudes, so if a person goes out of his way to show his parents honor in actions, it will help him internalize that honor and think of them respectfully as well. (This is besides the obligation of being דן לכף זכות that applies to all Jews.)
However, if after you really try to do this you still do not find it in your heart to look at your parents with respect, then you are an אונס, because you did whatever you could, and we cannot expect someone to do or say of think something that they are not able to.
As far as parents that violate the Torah, the obligation to honor parents in thought ("belev") and in action go hand in hand. Regarding parents that go against the Torah, the story is as follows:
The Rambam's opinion is that a person is obligated to honor his parents even if they are Reshayim. The Ramah brings an opinion that disagrees.
There is a disagreement in the poskim whether the Rambam is referring only to a parent who is just a "temporary Rasha," meaning, he is in general a Torah-observant Jew, but he has done some terrible things. But if a parent is constantly doing aveiros, or is totally non-observant, even the Rambam would agree that there is no Mitzvah of Kibud. Part of the reason for this is because if a person does a one-time sin, we can hope that he did Teshuva.
L'maaseh, if a parent does not keep the Torah at all, or constantly flagrantly violates the Torah, you do not need to be mechabed him, neither in actions or thoughts (assuming you are an Ashkenzai and follow the Ramah). That is certainly so if he does not believe in the Torah altogether. However, if his sinfulness was merely aberrational, you still should be mechabed him regardless of what he did.
Of course, that is the basic, bare-bones Halachah. By being respectful to parents who constantly sin, it is likely to be better for your Sholom Bayis, plus much more likely to help them do Teshuva. You accomplish more with honey than vinegar. However, in such a case, b'machshava you may think of them as they are.